27 April 2009

Pregnant Papas on the Beach

Today's predawn super low tide was spent on a tiny sliver of shore at Changi.This shore never fails to astound with an abundance of life. And this morning, we had many encounters with pregnant fathers.Many people are surprised to learn that Changi has many seahorses!James, who visited Changi for the first time with me this morning, found the first seahorse. It's large but really well camouflaged. Bravo James!Nearby in murkier waters, was another one. And stranded in the outgoing tide, was another one with a very bloated belly. He is a pregnant papa! In seahorses (Hippocampus sp.) it is the male that becomes 'pregnant' and carries the eggs. Here's more about how the papa gets 'pregnant'. And a few steps away, was another seahorse! This one with an angular belly and a tiny anal fin. Which shows that this is a mama seahorse.

Seahorses are often found in mated pairs, who are never far from one another. For those I've seen, generally, the females are yellow and males are more camouflaged in colour and pattern.

The baby seahorses emerge from papa's pouch as miniature seahorses. This special method of reproduction means seahorses reproduce slowly, and don't disperse very far. So removing seahorses from our shores can devastate local populations which may not recover. Seahorses can be trapped by abandoned nets and fishing lines, caught in litter or trampled by careless shore visitors.

The shores today were also teeming with Seagrass pipefishes!In the photo above are two pipefishes. The pink stuff is a red seaweed that incorporates calcium and is thus hard and crunchy.Stranded on the dry shore, I came across one pregnant papa pipefish (small photo at top left). Like the seahorse, the male pipefish also carries the eggs. These are usually carried under the long belly. When I gently placed him in some water, he flipped around (small photo on bottom left) and I couldn't see his belly anymore!

Besides the pipefishes, there were also lots of other animals on the shores. Here's a fluffy Swimming anemone (Boloceroides mcmurrichii) with a sea star. Sea stars are indeed a highlight of this shore.I saw lots of Biscuit sea stars (Gonodiscaster scaber), some Cake sea stars (Anthenea aspera) and one of the odd sea stars that we haven't figured out yet (photo on the right). As well as lots of Sand stars both plain and painted. Other echinoderms aplenty included Thorny sea cucumbers (Colochirus quadrangularis), Ball sea cucumbers (Phyllophorus sp.) and some Pink warty sea cucumbers (Cercodemas anceps).

As at Pulau Sekudu yesterday, the shores of Changi were covered with a bloom of Sea lettuce (Ulva sp.) a green seaweed that seasonally occurs in large quantities. This is not necessarily a bad thing as the seaweeds provide food and shelter for a wide variety of creatures. On Changi, among the many tiny animals found in the seaweeds were miniature Black sea urchins (Temnopleurus sp.) and really tiny spider crabs (Family Majoidea). While there were lots of White sea urchins (Salmacis sp.) on Pulau Sekudu yesterday, I didn't see any on Changi today.Well camouflaged prawns such as this Penaeid prawn (Family Penaeidae) and countless tiny shrimps also hid among the seaweeds.A special encounter was this pale orangey mantis shrimp. In shape it looks much like the Spearer mantis shrimps (Harpiosquilla sp.) that we often see on this shore. But the colouration is very different. It was very active and did not seem ill or injured.James spotted this bunch of wriggly brittle stars (Subclass Ophiuroidea) among the seaweeds.There were also large numbers of Geographic seahares (Syphonota geographica)! I didn't see any on Pulau Sekudu yesterday.On the soft silty parts of the shore, there were lots of Sand stars and buried Fan shells (Family Pinnidae).

This part of Changi has lush seagrass meadows, which are probably one of the reasons why there is so much life here. And among the usual Spoon seagrasses (Halophila ovalis), I spotted a patch of 'pointy' seagrasses.A closer look suggests there might be fine hairs on the leaf blade. Is this Halophila decipiens? Wow, that will be so cool if it were.

Among the last animals we encountered before leaving the shore was a large burrowing snail.Taking a closer look at it, it was a large and beautiful Noble volute (Cymbiola nobilis)! The living animal I feel is so much more handsome than the empty shell.

Although there were a few people walking around with plastic bags and buckets, this snail remained undisturbed. That's good to know!

free shore posters

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